It looks like your Blu-ray player with HDMI will be no problem. Dunno too much about PS3. I have no experience with them.
As for your Direct TV box, not knowing what outputs you have on it leaves me at a bit of a disadvantage. The specifications for your unit do say that it has audio inputs so you should be able to use either coaxial or optical digital outputs, assuming you have them or, at worst, red/white analog inputs which will provide an analog two-channel stereo signal.
Your best bet is to feed the DTV boxs video out directly to the TV and it's audio to the sound bar. It ain't pretty, but it'll work.
I will say that with only a yellow composite or S-video outputs, you're not gonna be too happy with that fine TV.